Proton pump inhibitors represented by omeprazole, which suppress secretion of gastric acid for the treatment of peptic ulcer, reflux esophagitis and the like, have been widely used in clinical situations. However, the existing proton pump inhibitors are associated with problems in terms of effect and side effects. To be specific, since the existing proton pump inhibitors are unstable under acidic conditions, they are often formulated as enteric preparations, in which case several hours are required before expression of the effect, and about 5 days to exhibit maximum efficacy by consecutive administration. In addition, since the existing proton pump inhibitors show inconsistent treatment effects due to metabolic enzyme polymorphism and drug interaction with pharmaceutical agents such as diazepam and the like, an improvement has been desired.
As pyrrole compounds having a proton pump inhibitory action, patent reference 1 describes a compound represented by the formula:
wherein X and Y are the same or different and each is a bond or a spacer having 1 to 20 atoms in the main chain, r1 is an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, r2, r3 and r4 are the same or different and each is a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted thienyl group, an optionally substituted benzo[b]thienyl group, an optionally substituted furyl group, an optionally substituted pyridyl group, an optionally substituted pyrazolyl group, an optionally substituted pyrimidinyl group, an acyl group, a halogen atom, a cyano group or a nitro group, and r5 and r6 are the same or different and each is a hydrogen atom or an optionally substituted hydrocarbon group.
In addition, as a therapeutic drug for neoplastic diseases or autoimmune diseases, patent reference 2 describes a compound represented by the formula:
wherein r7 is aryl, aralkyl, heteroaryl or the like, r8 is aryl, heteroaryl or the like, and r9 is aryl, heteroaryl, optionally substituted aminomethyl or the like.
[Patent reference 1] WO 2006/036024
[Patent reference 2] WO 2004/103968